I managed to find 57 eventually just through googling, but might have got it sooner if I hadn't been looking for a 3-word answer with 'and' in the middle...
The clue didn't mean anything to me. What the heck is a green cross man? Went looking with those words in mind and came up with "SPLINK!" Surely not, and went on and came upon another name and tried it with ticket agent and eureka!
Thanks for the great clue QuizmasterG, got it!! Funny, I'd looked at that several times in a list of agents, but didn't "see" it, if you know what I mean!!!